In 1882, Henry established the firm of C S Henry & Co.of London, metal merchants and copper importers of which he became managing director. The undertaking was converted into a Limited Liability Company in 1902. The venture was clearly a great success as by 1915 he was being described as a millionaire, and one biographer of David Lloyd George wrote of Henry that he was a self-made man who had made a fortune in South Africa

In the New Years Honours list for 1911, Henry became a baronet with the creation of the Henry Baronetcy, of Parkwood in the County of Berkshire. He also served as a Justice of the Peace for Berkshire. During the War, Henry was appointed to a number of important committees as he was identified as a loyal and sound occupant of the Coalition Liberal benches. He was a member of Lord Balfour's committee on After-War Trade, which was charged with looking at the possible introduction of the metric system to replace Britain's existing coinage, weights and measures. He also sat on a committee on Commercial and Industrial Policy, chaired by Lord Balfour of Burleigh. In July 1917, Henry was appointed to sit on the House of Commons Select Committee on Finance, chaired by Herbert Samuel. In 1918, Henry was chosen by the Minister of Munitions to chair a committee of inquiry into the staffing and conditions at the headquarters of the Ministry of Munitions and to suggest economies or improvements.Henry was also sometime president of the British Section of the Inter-Allied Parliamentary Committee.

He participated in Jewish welfare societies and other associations. In 1911, he laid the foundation stone of a synagogue at Southend. He also took a leading role in the financing and organisation of the Soup Kitchen for the Jewish Poor. In 1919 he was a prominent member of the organisation dedicated to the creation of a Jewish War Memorial to take the form of a fund of one million pounds for the endowment of Jewish religious education and the possible erection of a college for Jewish learning at Oxford or Cambridge.
This project, The Jewish Memorial Council, eventually funded Aria College in Portsmouth instead, a boarding school for Jewish boys to attend before going on to Jews College

In 1916 Cyril Henry Nursery School was founded in Woolwich as a Day and Night Nursery for children of local munitions workers in the Royal Arsenal. The nursery was funded by Lieutenant Henry’s mother Lady Julia Henry nee Lewisohn who part of a wealthy and philanthropic New York Jewish family. His father was Sir Charles Henry was a baronet and Liberal MP. He was their only child.

The work of the Nursery was depicted in a painting by Sir John Lavery, a WW1 war artist (currently in the Imperial War Museum). The building became a clinic following the war and then reverting to a Nursery during WW2 but always bearing the name Cyril Henry. In 2005 the Nursery was merged with Mulgrave Primary School and moved to new premises. The old building a rather interesting and well maintained wooden bungalow was sold and demolished.

Sir Charles Henry. ALTHOUGH this journal has not in very many important and vital matters concerning Jews, Been eye to eye with Sir CHARLES HENRY, we may be permitted to express a word of sincere regret at his all too untimely death. He held his views of the Jewish, needs and the Jewish destiny sincerely, "and he expressed them and fought for them with a vigour which did him nothing but honour, and which his opponents can appreciate. He possessed a genial personality, which endeared him to many friends,, and in all his actions there shone that ardent and unflinching patriotism which is one of the most honourable characteristics of the British-born Jew, as, indeed, of his coreligionists elsewhere, when they are given fair opportunity of manifesting it. The esteem in which he was everywhere held, and the real sorrow which his death has evoked in wide circles, are the best measure of the character of the man and the honest service he sought to do in his day.